1. Field of the Invention
The present invention relates to the field of humidifiers and more particularly to a humidifier capable of discharging mist having a temperature at a constant level.
2. Description of Related Art
Conventionally, humidifiers are used to increase humidity in the room in the continental climate areas. A conventional humidifier comprises a nebulizer (or a heater) for converting water into a fine cool (or hot) mist, and a blower for carrying the cool (or hot) mist out of the humidifier into the environment to be humidified wherein a water tank having an orifice on the bottom is vertically provided on a cavity of the lower space below the top of base. The cavity is served for retaining a liquid supplying to a cool (or hot) mist cavity and a valve is provided between the cavity for holding the water tank thereon and the cool (or hot) cavity. The opening or closing of the valve is controlled by the discharged liquid level of the cool (or hot) cavity. As such, the substantial amount of water supplied by the tank is varied up and down, i.e., not at a constant amount so that the temperature of mist discharged from the conventional humidifier can not be kept in constant. Further, mist is generated in the lower part of the space having a considerably height difference with the top adjacent to the inlet of discharging tube. As such, a high power motor is required to pump mist upwardly to reach to the inlet of discharging tube. In view of this, this prior art humidifier is not economical in saving energy and requires a relatively large motor and blower which in turn occupies a significant amount of space. It is known that water tank only occupies one fourth of the humidifier. As a result, a frequent liquid supplying operation is inevitable thus bothering user a lot.
Another drawback of this prior art humidifier is the manual water supplying operation because the only orifice of water tank is provided in the bottom. In other words, there is no top orifice on the water tank so user must periodically take empty water tank out of the cavity for supplying water therein.
Additionally, the cavity is always retaining liquid therein when the humidifier not used, micro-organism may easily grow in the bottom of the cavity thus not hygienic.
Furthermore, a combination of cool and warm mist is not available in most conventional humidifiers because most commonly used high frequency ultrasonic transducers having a nebulizer are not designed to operate in a high temperature environment. In other words, a shortened life is anticipated if it does operate in such condition. One may use a nebulizer capable of operating in high temperature. However, the high cost of buying such nebulizer makes it impractical in fact.
Thus, it is desirable to provide an improved humidifier in order to overcome the above drawbacks of prior art.